Earthquakes and volcanic eruption make for disastrous month in Mexico

A string of natural disasters in Mexico has left the country reeling as three earthquakes and a volcanic eruption have ravaged the region around Mexico City.

On September 8th, an earthquake registering 8.1 on the Richter Scale struck just off the coast of the Mexican state of Chiapas, on the southwest Pacific coast. The epicenter was approximately 600 miles (1,000 km) southeast of Mexico City, which was rocked by the temblor. According to Mexican President Enrique Peña Nieto, the quake was the strongest that Mexico has experienced since a 7.9 quake in 1902. At least 96 people died, tsunami warnings were triggered, and much of the city of Juchitan, in the state of Oaxaca, collapsed into rubble.

Eleven days later, on September 19th, another earthquake hit the region, this time a 7.1 quake in the state of Puebla. This quake, though of lesser magnitude, was much more damaging, as the epicenter was much closer to Mexico City, centered in the town of Raboso, about 76 miles (123 km) southeast of Mexico City. Over 340 deaths have been reported, and estimates of the cost of damage range from two to eight billion dollars.

Saturday, September 21st, saw another earthquake strike the region: a 6.1 magnitude quake centered in the state of Oaxaca near the town of Matias Romero, approximately 275 miles southeast of Mexico City, roughly between the centers of the two earlier, more violent earthquakes. The earthquakes are thought to be too far apart to be related to each other.

As if three earthquakes greater than 6.0 magnitude within 15 days weren’t enough to deal with, the seismic activity has touched off a volcanic eruption at the Popocatepetl volcano, an active volcano 45 miles (72.5 km) southeast of Mexico City. The volcano has been active at a low level for 23 years. The volcano, which periodically belches smoke and ash, erupted with a shower of lava and rocks after the quake, though fortunately the eruption remained at a relatively low level. Mexico’s volcano-monitoring system registered one notable explosion and 256 low-intensity “exhalations” between September 17th and 18th. Because of its location, a major eruption could potentially affect 20 million Mexicans.

Mexico, and Mexico City in particular, are especially vulnerable to seismic activity because of location: Mexico is located at the junction of five tectonic plates, and Mexico City itself sits on a former lake bed, an unstable terrain for one of the world’s largest cities. The land under Mexico City is unconsolidated sediment, meaning that a quake can cause shaking much like a bowl of gelatin. The quakes were likely caused by the Cocos plate subducting under the North American plate. Whether or not the movement that caused the quakes also caused the eruption of Popocatepetl is in question. Mexico’s National Center for Prevention of Disasters said none of the volcanic activity can be attributed to the earthquake. Eruptions occur at the volcano approximately twice a year, on average. Other experts are unwilling to dismiss a potential connection.

Rebuilding will be costly, and Peña Nieto warns that financial resources are limited, and Congress, which is meeting now, must focus on making funds available for reconstruction and rehabilitation in 2018.